The subjective perception of value

It is Black Friday today, with Cyber Monday coming up. Of course there is a sale on Steam. Before Steam I used to buy games when they came out, because it was often difficult to get hold of a copy a year later in a brick-and-mortar shop. But these days I only buy games at release when I really can't wait to play them, for example XCOM: Enemy Unknown. Games that are released where I just think "oh, I might want to play that one day" go on my wishlist instead. And when Steam does a sale, I check

World of Warkraft...